Date Awarded

1973

Document Type

Thesis

Degree Name

Master of Arts (M.A.)

Department

Virginia Institute of Marine Science

Advisor

Maynard M. Nichols

Committee Member

Robert L. Ellison

Committee Member

Jay D. Andrews

Abstract

Foraminiferal faunas in marshes and distributary channels of the James River estuary, Virginia, disclose several facies. The channel facies, primarily Ammobaculites crassus, and A. sp. A, typical of estuaries in Chesapeake Bay and other brackish areas are readily distinguishable freom the march facies. Marshes are divisible laterally by changes in the relative proportions of marsh species such as Miliammina fusca, Ammoastuta salsa, and Haplophragmoides hancocki.Changes along the longitudinal estuarine salinity gradient are discernable in both tidal creeks and marsh. Channels exhibit a longitudinal gradient from a freshwater thecamoebinid facies through an upper and mid-estuarine Ammobaculites facies to a higher salinity Elphidium assemblage. Marshes are divisible into thecamoebinid, Ammoastuta-Miliammina and Miliammina zones. Macroscopic marsh floral zones along the estuary exhibit changes which are similar to, but do not mirror, changes in foraminiferal facies. Both distributions are responses to salinity and elevation above Mean Low Water. Paleocological inferences are drawn from data on distributions of marsh microfaunas. This dissertation is from the Joint Program Degree from the College of William & Mary and University of Virginia and awarded by the University of Virginia.

DOI

https://doi.org/10.25773/TT12-4Q33

Rights

© The Author

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